3 Headed Ghast Boss Add-on Minecraft PE

You should note that creature, which is provided by 3 Headed Ghast Boss, is naturally hostile to every player and it replaces the vanilla Ghast, so you can meet it spawning naturally. If you need this boss to appear in the Overwolrd, just use the spawn egg.

This creature appear in Minecraft PE story mode and we may consider it as one of the most powerful bosses. It has enormous amount of health (400 hearts), shoots extremely fast burning balls, which deal 18 direct damage each, but the drop is generous, so the entire fight with Ghast Boss is totally worth it.